def __init__(self, dimension, alphabet_size, **kwargs):
super(WordReverser, self).__init__(**kwargs)
encoder = Bidirectional(
SimpleRecurrent(dim=dimension, activation=Tanh()))
fork = Fork([name for name in encoder.prototype.apply.sequences
if name != 'mask'])
fork.input_dim = dimension
fork.output_dims = [dimension for name in fork.input_names]
lookup = LookupTable(alphabet_size, dimension)
transition = SimpleRecurrent(
activation=Tanh(),
dim=dimension, name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=2 * dimension, match_dim=dimension, name="attention")
readout = Readout(
readout_dim=alphabet_size,
source_names=[transition.apply.states[0],
attention.take_glimpses.outputs[0]],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(alphabet_size, dimension),
name="readout")
generator = SequenceGenerator(
readout=readout, transition=transition, attention=attention,
name="generator")
self.lookup = lookup
self.fork = fork
self.encoder = encoder
self.generator = generator
self.children = [lookup, fork, encoder, generator]
def __init__(self, dimen, vocab_size): #{
# No idea what this is doing, but otherwise "allocated" is not set
super(MorphGen, self).__init__(self)
# The encoder
encoder = Bidirectional(SimpleRecurrent(dim=dimen, activation=Tanh()))
# What is this doing ?
fork = Fork([name for name in encoder.prototype.apply.sequences if name != 'mask'])
fork.input_dim = dimen
fork.output_dims = [encoder.prototype.get_dim(name) for name in fork.input_names]
lookup = LookupTable(vocab_size, dimen)
transition = SimpleRecurrent(dim=dimen, activation=Tanh(), name="transition")
atten = SequenceContentAttention(state_names=transition.apply.states,attended_dim=2*dimen, match_dim=dimen, name="attention")
readout = Readout(
readout_dim=vocab_size,
source_names=[transition.apply.states[0],
atten.take_glimpses.outputs[0]],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(vocab_size, dimen),
name="readout");
generator = SequenceGenerator(readout=readout, transition=transition, attention=atten,name="generator")
self.lookup = lookup
self.fork = fork
self.encoder = encoder
self.generator = generator
self.children = [lookup, fork, encoder, generator]
def __init__(self, path, nn_char_map, no_transition_cost=1e12, **kwargs):
# Since we currently support only type, it is ignored.
# if type_ != 'fst':
# raise ValueError("Supports only FST's so far.")
fst = FST(path)
fst_char_map = dict(fst.fst.isyms.items())
del fst_char_map['<eps>']
if not len(fst_char_map) == len(nn_char_map):
raise ValueError()
remap_table = {
nn_char_map[character]: fst_code
for character, fst_code in fst_char_map.items()
}
transition = FSTTransition(fst, remap_table, no_transition_cost)
# This SequenceGenerator will be used only in a very limited way.
# That's why it is sufficient to equip it with a completely
# fake readout.
dummy_readout = Readout(source_names=['add'],
readout_dim=len(remap_table),
merge=Merge(input_names=['costs'],
prototype=Identity()),
post_merge=Identity(),
emitter=SoftmaxEmitter())
super(LanguageModel,
self).__init__(transition=transition,
fork=Fork(output_names=[
name for name in transition.apply.sequences
if name != 'mask'
],
prototype=Identity()),
readout=dummy_readout,
**kwargs)
def __init__(self, dimension, alphabet_size, **kwargs):
super(SimpleGenerator, self).__init__(**kwargs)
lookup = LookupTable(alphabet_size, dimension)
transition = SimpleRecurrent(activation=Tanh(),
dim=dimension,
name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=dimension,
match_dim=dimension,
name="attention")
readout = Readout(readout_dim=alphabet_size,
source_names=[
transition.apply.states[0],
attention.take_glimpses.outputs[0]
],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(
alphabet_size, dimension),
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
name="generator")
self.lookup = lookup
self.generator = generator
self.children = [lookup, generator]
def getRnnGenerator(vocab_size,hidden_dim,input_dim=512):
"""
"Apply" the RNN to the input x
For initializing the network, the vocab size needs to be known
Default of the hidden layer is set tot 512 like Karpathy
"""
generator = SequenceGenerator(
Readout(readout_dim = vocab_size,
source_names = ["states"], # transition.apply.states ???
emitter = SoftmaxEmitter(name="emitter"),
feedback_brick = LookupFeedback(
vocab_size,
input_dim,
name = 'feedback'
),
name = "readout"
),
MySimpleRecurrent(
name = "transition",
activation = Tanh(),
dim = hidden_dim
),
weights_init = IsotropicGaussian(0.01),
biases_init = Constant(0),
name = "generator"
)
generator.push_initialization_config()
generator.transition.weights_init = IsotropicGaussian(0.01)
generator.initialize()
return generator
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim,topical_dim,theano_seed=None, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
#self.topical_dim=topical_dim;
# Initialize gru with special initial state
self.transition = GRUInitialState(
attended_dim=state_dim, dim=state_dim,
activation=Tanh(), name='decoder')
# Initialize the attention mechanism
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim, name="attention")
self.topical_attention=SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=topical_dim,
match_dim=state_dim, name="topical_attention")#not sure whether the match dim would be correct.
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
readout = Readout(
source_names=['states', 'feedback',
self.attention.take_glimpses.outputs[0]],#check!
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1, theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence(
[Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2, output_dim=embedding_dim,
use_bias=False, name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply]),
merged_dim=state_dim)
# Build sequence generator accordingly
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
topical_attention=self.topical_attention,
topical_name='topical_embeddingq',
content_name='content_embedding',
fork=Fork([name for name in self.transition.apply.sequences
if name != 'mask'], prototype=Linear())
)
self.children = [self.sequence_generator]
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.transition = GRUInitialState(attended_dim=state_dim,
dim=state_dim,
activation=Tanh(),
name='decoder')
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim,
name="attention")
readout = Readout(source_names=[
'states', 'feedback', self.attention.take_glimpses.outputs[0]
],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1),
feedback_brick=LookupFeedbackWMT15(
vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Linear(input_dim=embedding_dim,
name='softmax1').apply
]),
merged_dim=state_dim,
merge_prototype=Linear(use_bias=True))
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name
for name in self.transition.apply.sequences if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
def test_integer_sequence_generator():
# Disclaimer: here we only check shapes, not values.
readout_dim = 5
feedback_dim = 3
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(name="transition",
activation=Tanh(),
dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(LinearReadout(
readout_dim=readout_dim,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(readout_dim, feedback_dim),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
generator.initialize()
y = tensor.lmatrix('y')
mask = tensor.matrix('mask')
costs = generator.cost(y, mask)
assert costs.ndim == 2
costs_val = theano.function([y, mask],
[costs])(numpy.zeros((n_steps, batch_size),
dtype='int64'),
numpy.ones((n_steps, batch_size),
dtype=floatX))[0]
assert costs_val.shape == (n_steps, batch_size)
states, outputs, costs = generator.generate(iterate=True,
batch_size=batch_size,
n_steps=n_steps)
states_val, outputs_val, costs_val = theano.function(
[], [states, outputs, costs],
updates=costs.owner.inputs[0].owner.tag.updates)()
assert states_val.shape == (n_steps, batch_size, dim)
assert outputs_val.shape == (n_steps, batch_size)
assert outputs_val.dtype == 'int64'
assert costs_val.shape == (n_steps, batch_size)
def __init__(self, vocab_size, embedding_dim, state_dim,
representation_dim, **kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
readout = Readout(
source_names=['states', 'feedback', 'readout_context'],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(),
feedback_brick=LookupFeedback(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=1000).apply,
Maxout(num_pieces=2).apply,
Linear(input_dim=state_dim / 2, output_dim=100,
use_bias=False).apply,
Linear(input_dim=100).apply
]),
merged_dim=1000)
self.transition = GatedRecurrentWithContext(Tanh(),
dim=state_dim,
name='decoder')
# Readout will apply the linear transformation to 'readout_context'
# with a Merge brick, so no need to fork it here
self.fork = Fork([
name for name in self.transition.apply.contexts +
self.transition.apply.states if name != 'readout_context'
],
prototype=Linear())
self.tanh = Tanh()
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
fork_inputs=[
name for name in self.transition.apply.sequences
if name != 'mask'
],
)
self.children = [self.fork, self.sequence_generator, self.tanh]
def __init__(self,
vocab_size,
embedding_dim,
dgru_state_dim,
igru_state_dim,
state_dim,
representation_dim,
transition_depth,
trg_igru_depth,
trg_dgru_depth,
trg_space_idx,
trg_bos,
theano_seed=None,
**kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.dgru_state_dim = dgru_state_dim
self.igru_state_dim = igru_state_dim
self.state_dim = state_dim
self.trg_space_idx = trg_space_idx
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = RecurrentStack([
GRUInitialState(attended_dim=state_dim,
dim=state_dim,
activation=Tanh(),
name='decoder_gru_withinit')
] + [
GatedRecurrent(
dim=state_dim, activation=Tanh(), name='decoder_gru' + str(i))
for i in range(1, transition_depth)
],
skip_connections=False)
# Initialize the attention mechanism
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim,
name="attention")
self.interpolator = Interpolator(
vocab_size=vocab_size,
embedding_dim=embedding_dim,
igru_state_dim=igru_state_dim,
igru_depth=trg_igru_depth,
trg_dgru_depth=trg_dgru_depth,
source_names=[
'states', 'feedback', self.attention.take_glimpses.outputs[0]
],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=trg_bos,
theano_seed=theano_seed),
feedback_brick=TargetWordEncoder(vocab_size, embedding_dim,
self.dgru_state_dim,
trg_dgru_depth))
# Build sequence generator accordingly
self.sequence_generator = SequenceGeneratorDCNMT(
trg_space_idx=self.trg_space_idx,
readout=self.interpolator,
transition=self.transition,
attention=self.attention,
transition_depth=transition_depth,
igru_depth=trg_igru_depth,
trg_dgru_depth=trg_dgru_depth,
fork=Fork([
name
for name in self.transition.apply.sequences if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
def __init__(self,
vocab_size,
topicWord_size,
embedding_dim,
state_dim,
topical_dim,
representation_dim,
match_function='SumMacthFunction',
use_doubly_stochastic=False,
lambda_ds=0.001,
use_local_attention=False,
window_size=10,
use_step_decay_cost=False,
use_concentration_cost=False,
lambda_ct=10,
use_stablilizer=False,
lambda_st=50,
theano_seed=None,
**kwargs):
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.topicWord_size = topicWord_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRU(attended_dim=state_dim,
dim=state_dim,
activation=Tanh(),
name='decoder')
self.energy_computer = globals()[match_function](name='energy_comp')
# Initialize the attention mechanism
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim,
energy_computer=self.energy_computer,
use_local_attention=use_local_attention,
window_size=window_size,
name="attention")
self.topical_attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=topical_dim,
match_dim=state_dim,
energy_computer=self.energy_computer,
use_local_attention=use_local_attention,
window_size=window_size,
name="topical_attention"
) #not sure whether the match dim would be correct.
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
readout = Readout(source_names=[
'states', 'feedback', self.attention.take_glimpses.outputs[0]
],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1,
theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(
vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Linear(input_dim=embedding_dim,
name='softmax1').apply
]),
merged_dim=state_dim,
name='readout')
# calculate the readout of topic word,
# no specific feedback brick, use the trival feedback break
# no post_merge and merge, use Bias and Linear
topicWordReadout = Readout(source_names=[
'states', 'feedback', self.attention.take_glimpses.outputs[0]
],
readout_dim=self.topicWord_size,
emitter=SoftmaxEmitter(
initial_output=-1,
theano_seed=theano_seed),
name='twReadout')
# Build sequence generator accordingly
self.sequence_generator = SequenceGenerator(
readout=readout,
topicWordReadout=topicWordReadout,
topic_vector_names=['topicSumVector'],
transition=self.transition,
attention=self.attention,
topical_attention=self.topical_attention,
q_dim=self.state_dim,
#q_name='topic_embedding',
topical_name='topic_embedding',
content_name='content_embedding',
use_step_decay_cost=use_step_decay_cost,
use_doubly_stochastic=use_doubly_stochastic,
lambda_ds=lambda_ds,
use_concentration_cost=use_concentration_cost,
lambda_ct=lambda_ct,
use_stablilizer=use_stablilizer,
lambda_st=lambda_st,
fork=Fork([
name
for name in self.transition.apply.sequences if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
def main():
logging.basicConfig(
level=logging.DEBUG,
format="%(asctime)s: %(name)s: %(levelname)s: %(message)s")
parser = argparse.ArgumentParser(
"Case study of language modeling with RNN",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument(
"mode",
choices=["train", "sample"],
help="The mode to run. Use `train` to train a new model"
" and `sample` to sample a sequence generated by an"
" existing one.")
parser.add_argument("prefix",
default="sine",
help="The prefix for model, timing and state files")
parser.add_argument("state",
nargs="?",
default="",
help="Changes to Groundhog state")
parser.add_argument("--path", help="Path to a language dataset")
parser.add_argument("--dict", help="Path to the dataset dictionary")
parser.add_argument("--restart", help="Start anew")
parser.add_argument("--reset",
action="store_true",
default=False,
help="Reset the hidden state between batches")
parser.add_argument("--steps",
type=int,
default=100,
help="Number of steps to plot for the 'sample' mode"
" OR training sequence length for the 'train' mode.")
args = parser.parse_args()
logger.debug("Args:\n" + str(args))
dim = 200
num_chars = 50
transition = GatedRecurrent(name="transition",
activation=Tanh(),
dim=dim,
weights_init=Orthogonal())
generator = SequenceGenerator(LinearReadout(
readout_dim=num_chars,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(num_chars, dim, name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
generator.allocate()
logger.debug("Parameters:\n" + pprint.pformat(
[(key, value.get_value().shape)
for key, value in Selector(generator).get_params().items()],
width=120))
if args.mode == "train":
batch_size = 1
seq_len = args.steps
generator.initialize()
# Build cost computation graph that uses the saved hidden states.
# An issue: for Groundhog this is completely transparent, that's
# why it does not carry the hidden state over the period when
# validation in done. We should find a way to fix in the future.
x = tensor.lmatrix('x')
init_states = shared_floatx_zeros((batch_size, dim),
name='init_states')
reset = tensor.scalar('reset')
cost = ComputationGraph(
generator.cost(x, states=init_states * reset).sum())
# TODO: better search routine
states = [
v for v in cost.variables if hasattr(v.tag, 'application_call')
and v.tag.application_call.brick == generator.transition and
(v.tag.application_call.application == generator.transition.apply)
and v.tag.role == VariableRole.OUTPUT and v.tag.name == 'states'
]
assert len(states) == 1
states = states[0]
gh_model = GroundhogModel(generator, cost)
gh_model.properties.append(
('bpc', cost.outputs[0] * numpy.log(2) / seq_len))
gh_model.properties.append(('mean_init_state', init_states.mean()))
gh_model.properties.append(('reset', reset))
if not args.reset:
gh_model.updates.append((init_states, states[-1]))
state = GroundhogState(args.prefix, batch_size,
learning_rate=0.0001).as_dict()
changes = eval("dict({})".format(args.state))
state.update(changes)
def output_format(x, y, reset):
return dict(x=x[:, None], reset=reset)
train, valid, test = [
LMIterator(batch_size=batch_size,
use_infinite_loop=mode == 'train',
path=args.path,
seq_len=seq_len,
mode=mode,
chunks='chars',
output_format=output_format,
can_fit=True) for mode in ['train', 'valid', 'test']
]
trainer = SGD(gh_model, state, train)
state['on_nan'] = 'warn'
state['cutoff'] = 1.
main_loop = MainLoop(train, valid, None, gh_model, trainer, state,
None)
if not args.restart:
main_loop.load()
main_loop.main()
elif args.mode == "sample":
load_params(generator, args.prefix + "model.npz")
chars = numpy.load(args.dict)['unique_chars']
sample = ComputationGraph(
generator.generate(n_steps=args.steps, batch_size=10,
iterate=True)).function()
states, outputs, costs = sample()
for i in range(10):
print("Generation cost: {}".format(costs[:, i].sum()))
print("".join([chars[o] for o in outputs[:, i]]))
else:
assert False
def main(mode, save_path, num_batches, from_dump):
if mode == "train":
# Experiment configuration
dimension = 100
readout_dimension = len(char2code)
# Data processing pipeline
data_stream = DataStreamMapping(
mapping=lambda data: tuple(array.T for array in data),
data_stream=PaddingDataStream(
BatchDataStream(
iteration_scheme=ConstantScheme(10),
data_stream=DataStreamMapping(
mapping=reverse_words,
add_sources=("targets", ),
data_stream=DataStreamFilter(
predicate=lambda data: len(data[0]) <= 100,
data_stream=OneBillionWord(
"training", [99],
char2code,
level="character",
preprocess=str.lower).get_default_stream())))))
# Build the model
chars = tensor.lmatrix("features")
chars_mask = tensor.matrix("features_mask")
targets = tensor.lmatrix("targets")
targets_mask = tensor.matrix("targets_mask")
encoder = Bidirectional(GatedRecurrent(dim=dimension,
activation=Tanh()),
weights_init=Orthogonal())
encoder.initialize()
fork = Fork([
name
for name in encoder.prototype.apply.sequences if name != 'mask'
],
weights_init=IsotropicGaussian(0.1),
biases_init=Constant(0))
fork.input_dim = dimension
fork.fork_dims = {name: dimension for name in fork.fork_names}
fork.initialize()
lookup = LookupTable(readout_dimension,
dimension,
weights_init=IsotropicGaussian(0.1))
lookup.initialize()
transition = Transition(activation=Tanh(),
dim=dimension,
attended_dim=2 * dimension,
name="transition")
attention = SequenceContentAttention(
state_names=transition.apply.states,
match_dim=dimension,
name="attention")
readout = LinearReadout(readout_dim=readout_dimension,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(
readout_dimension, dimension),
name="readout")
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
weights_init=IsotropicGaussian(0.1),
biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
bricks = [encoder, fork, lookup, generator]
# Give an idea of what's going on
params = Selector(bricks).get_params()
logger.info("Parameters:\n" +
pprint.pformat([(key, value.get_value().shape)
for key, value in params.items()],
width=120))
# Build the cost computation graph
batch_cost = generator.cost(
targets,
targets_mask,
attended=encoder.apply(**dict_union(fork.apply(
lookup.lookup(chars), return_dict=True),
mask=chars_mask)),
attended_mask=chars_mask).sum()
batch_size = named_copy(chars.shape[1], "batch_size")
cost = aggregation.mean(batch_cost, batch_size)
cost.name = "sequence_log_likelihood"
logger.info("Cost graph is built")
# Fetch variables useful for debugging
max_length = named_copy(chars.shape[0], "max_length")
cost_per_character = named_copy(
aggregation.mean(batch_cost, batch_size * max_length),
"character_log_likelihood")
cg = ComputationGraph(cost)
energies = unpack(VariableFilter(application=readout.readout,
name="output")(cg.variables),
singleton=True)
min_energy = named_copy(energies.min(), "min_energy")
max_energy = named_copy(energies.max(), "max_energy")
(activations, ) = VariableFilter(
application=generator.transition.apply,
name="states")(cg.variables)
mean_activation = named_copy(activations.mean(), "mean_activation")
# Define the training algorithm.
algorithm = GradientDescent(cost=cost,
step_rule=CompositeRule([
GradientClipping(10.0),
SteepestDescent(0.01)
]))
observables = [
cost, min_energy, max_energy, mean_activation, batch_size,
max_length, cost_per_character, algorithm.total_step_norm,
algorithm.total_gradient_norm
]
for name, param in params.items():
observables.append(named_copy(param.norm(2), name + "_norm"))
observables.append(
named_copy(algorithm.gradients[param].norm(2),
name + "_grad_norm"))
main_loop = MainLoop(
model=bricks,
data_stream=data_stream,
algorithm=algorithm,
extensions=([LoadFromDump(from_dump)] if from_dump else []) + [
Timing(),
TrainingDataMonitoring(observables, after_every_batch=True),
TrainingDataMonitoring(
observables, prefix="average", every_n_batches=10),
FinishAfter(after_n_batches=num_batches).add_condition(
"after_batch", lambda log: math.isnan(
log.current_row.total_gradient_norm)),
Plot(os.path.basename(save_path),
[["average_" + cost.name],
["average_" + cost_per_character.name]],
every_n_batches=10),
SerializeMainLoop(save_path,
every_n_batches=500,
save_separately=["model", "log"]),
Printing(every_n_batches=1)
])
main_loop.run()
elif mode == "test":
with open(save_path, "rb") as source:
encoder, fork, lookup, generator = dill.load(source)
logger.info("Model is loaded")
chars = tensor.lmatrix("features")
generated = generator.generate(
n_steps=3 * chars.shape[0],
batch_size=chars.shape[1],
attended=encoder.apply(**dict_union(
fork.apply(lookup.lookup(chars), return_dict=True))),
attended_mask=tensor.ones(chars.shape))
sample_function = ComputationGraph(generated).get_theano_function()
logging.info("Sampling function is compiled")
while True:
# Python 2-3 compatibility
line = input("Enter a sentence\n")
batch_size = int(input("Enter a number of samples\n"))
encoded_input = [
char2code.get(char, char2code["<UNK>"])
for char in line.lower().strip()
]
encoded_input = ([char2code['<S>']] + encoded_input +
[char2code['</S>']])
print("Encoder input:", encoded_input)
target = reverse_words((encoded_input, ))[0]
print("Target: ", target)
states, samples, glimpses, weights, costs = sample_function(
numpy.repeat(numpy.array(encoded_input)[:, None],
batch_size,
axis=1))
messages = []
for i in range(samples.shape[1]):
sample = list(samples[:, i])
try:
true_length = sample.index(char2code['</S>']) + 1
except ValueError:
true_length = len(sample)
sample = sample[:true_length]
cost = costs[:true_length, i].sum()
message = "({})".format(cost)
message += "".join(code2char[code] for code in sample)
if sample == target:
message += " CORRECT!"
messages.append((cost, message))
messages.sort(key=lambda tuple_: -tuple_[0])
for _, message in messages:
print(message)
eos_token=None,
unk_token='<UNK>',
level='character')
alphabet_size = 4
lstm_dim = 2
lstm1 = LSTM(dim=lstm_dim, use_bias=False, weights_init=Orthogonal())
lstm2 = LSTM(dim=lstm_dim, use_bias=False, weights_init=Orthogonal())
rnn = RecurrentStack([lstm1, lstm2], name="transition")
readout = Readout(readout_dim=alphabet_size,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(alphabet_size,
feedback_dim=alphabet_size,
name="feedback"),
name="readout")
seq_gen = SequenceGenerator(readout=readout,
transition=rnn,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
seq_gen.push_initialization_config()
rnn.weights_init = Orthogonal()
seq_gen.initialize()
def __init__(self, initial_output='\n'):
self.theano_rng = MRG_RandomStreams(seed=random.randint(0,100000))
SoftmaxEmitter.__init__(self, initial_output=initial_output)
def __init__(
self,
input_dims,
input_num_chars,
eos_label,
num_phonemes,
dim_dec,
dims_bidir,
enc_transition,
dec_transition,
use_states_for_readout,
attention_type,
criterion,
bottom,
lm=None,
character_map=None,
bidir=True,
subsample=None,
dims_top=None,
prior=None,
conv_n=None,
post_merge_activation=None,
post_merge_dims=None,
dim_matcher=None,
embed_outputs=True,
dim_output_embedding=None,
dec_stack=1,
conv_num_filters=1,
data_prepend_eos=True,
# softmax is the default set in SequenceContentAndConvAttention
energy_normalizer=None,
# for speech this is the approximate phoneme duration in frames
max_decoded_length_scale=1,
**kwargs):
if post_merge_activation is None:
post_merge_activation = Tanh()
super(SpeechRecognizer, self).__init__(**kwargs)
self.eos_label = eos_label
self.data_prepend_eos = data_prepend_eos
self.rec_weights_init = None
self.initial_states_init = None
self.enc_transition = enc_transition
self.dec_transition = dec_transition
self.dec_stack = dec_stack
self.criterion = criterion
self.max_decoded_length_scale = max_decoded_length_scale
post_merge_activation = post_merge_activation
if dim_matcher is None:
dim_matcher = dim_dec
# The bottom part, before BiRNN
bottom_class = bottom.pop('bottom_class')
bottom = bottom_class(input_dims=input_dims,
input_num_chars=input_num_chars,
name='bottom',
**bottom)
# BiRNN
if not subsample:
subsample = [1] * len(dims_bidir)
encoder = Encoder(self.enc_transition,
dims_bidir,
bottom.get_dim(bottom.apply.outputs[0]),
subsample,
bidir=bidir)
dim_encoded = encoder.get_dim(encoder.apply.outputs[0])
generators = [None, None]
for i in range(2):
# The top part, on top of BiRNN but before the attention
if dims_top:
top = MLP([Tanh()], [dim_encoded] + dims_top + [dim_encoded],
name="top{}".format(i))
else:
top = Identity(name='top{}'.format(i))
if dec_stack == 1:
transition = self.dec_transition(dim=dim_dec,
activation=Tanh(),
name="transition{}".format(i))
else:
transitions = [
self.dec_transition(dim=dim_dec,
activation=Tanh(),
name="transition_{}_{}".format(
i, trans_level))
for trans_level in xrange(dec_stack)
]
transition = RecurrentStack(transitions=transitions,
skip_connections=True)
# Choose attention mechanism according to the configuration
if attention_type == "content":
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=dim_encoded,
match_dim=dim_matcher,
name="cont_att" + i)
elif attention_type == "content_and_conv":
attention = SequenceContentAndConvAttention(
state_names=transition.apply.states,
conv_n=conv_n,
conv_num_filters=conv_num_filters,
attended_dim=dim_encoded,
match_dim=dim_matcher,
prior=prior,
energy_normalizer=energy_normalizer,
name="conv_att{}".format(i))
else:
raise ValueError(
"Unknown attention type {}".format(attention_type))
if embed_outputs:
feedback = LookupFeedback(
num_phonemes + 1, dim_dec
if dim_output_embedding is None else dim_output_embedding)
else:
feedback = OneOfNFeedback(num_phonemes + 1)
if criterion['name'] == 'log_likelihood':
emitter = SoftmaxEmitter(initial_output=num_phonemes,
name="emitter{}".format(i))
if lm:
# In case we use LM it is Readout that is responsible
# for normalization.
emitter = LMEmitter()
elif criterion['name'].startswith('mse'):
emitter = RewardRegressionEmitter(criterion['name'],
eos_label,
num_phonemes,
criterion.get(
'min_reward', -1.0),
name="emitter")
else:
raise ValueError("Unknown criterion {}".format(
criterion['name']))
readout_config = dict(
readout_dim=num_phonemes,
source_names=(transition.apply.states if use_states_for_readout
else []) + [attention.take_glimpses.outputs[0]],
emitter=emitter,
feedback_brick=feedback,
name="readout{}".format(i))
if post_merge_dims:
readout_config['merged_dim'] = post_merge_dims[0]
readout_config['post_merge'] = InitializableSequence(
[
Bias(post_merge_dims[0]).apply,
post_merge_activation.apply,
MLP(
[post_merge_activation] *
(len(post_merge_dims) - 1) + [Identity()],
# MLP was designed to support Maxout is activation
# (because Maxout in a way is not one). However
# a single layer Maxout network works with the trick below.
# For deeper Maxout network one has to use the
# Sequence brick.
[
d //
getattr(post_merge_activation, 'num_pieces', 1)
for d in post_merge_dims
] + [num_phonemes]).apply,
],
name='post_merge{}'.format(i))
readout = Readout(**readout_config)
language_model = None
if lm and lm.get('path'):
lm_weight = lm.pop('weight', 0.0)
normalize_am_weights = lm.pop('normalize_am_weights', True)
normalize_lm_weights = lm.pop('normalize_lm_weights', False)
normalize_tot_weights = lm.pop('normalize_tot_weights', False)
am_beta = lm.pop('am_beta', 1.0)
if normalize_am_weights + normalize_lm_weights + normalize_tot_weights < 1:
logger.warn(
"Beam search is prone to fail with no log-prob normalization"
)
language_model = LanguageModel(nn_char_map=character_map, **lm)
readout = ShallowFusionReadout(
lm_costs_name='lm_add',
lm_weight=lm_weight,
normalize_am_weights=normalize_am_weights,
normalize_lm_weights=normalize_lm_weights,
normalize_tot_weights=normalize_tot_weights,
am_beta=am_beta,
**readout_config)
generators[i] = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
language_model=language_model,
name="generator{}".format(i))
self.generator = generators[0]
self.forward_to_backward = Linear(dim_dec, dim_dec)
# Remember child bricks
self.encoder = encoder
self.bottom = bottom
self.top = top
self.generators = generators
self.children = [self.forward_to_backward, encoder, top, bottom
] + generators
# Create input variables
self.inputs = self.bottom.batch_inputs
self.inputs_mask = self.bottom.mask
self.labels = tensor.lmatrix('labels')
self.labels_mask = tensor.matrix("labels_mask")
self.single_inputs = self.bottom.single_inputs
self.single_labels = tensor.lvector('labels')
self.n_steps = tensor.lscalar('n_steps')
def test_sequence_generator_with_lm():
floatX = theano.config.floatX
rng = numpy.random.RandomState(1234)
readout_dim = 5
feedback_dim = 3
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(dim=dim,
activation=Tanh(),
weights_init=Orthogonal())
language_model = SequenceGenerator(Readout(
readout_dim=readout_dim,
source_names=["states"],
emitter=SoftmaxEmitter(theano_seed=1234),
feedback_brick=LookupFeedback(readout_dim, dim, name='feedback')),
SimpleRecurrent(dim, Tanh()),
name='language_model')
generator = SequenceGenerator(Readout(
readout_dim=readout_dim,
source_names=["states", "lm_states"],
emitter=SoftmaxEmitter(theano_seed=1234),
feedback_brick=LookupFeedback(readout_dim, feedback_dim)),
transition,
language_model=language_model,
weights_init=IsotropicGaussian(0.1),
biases_init=Constant(0),
seed=1234)
generator.initialize()
# Test 'cost_matrix' method
y = tensor.lmatrix('y')
y.tag.test_value = numpy.zeros((15, batch_size), dtype='int64')
mask = tensor.matrix('mask')
mask.tag.test_value = numpy.ones((15, batch_size))
costs = generator.cost_matrix(y, mask)
assert costs.ndim == 2
costs_fun = theano.function([y, mask], [costs])
y_test = rng.randint(readout_dim, size=(n_steps, batch_size))
m_test = numpy.ones((n_steps, batch_size), dtype=floatX)
costs_val = costs_fun(y_test, m_test)[0]
assert costs_val.shape == (n_steps, batch_size)
assert_allclose(costs_val.sum(), 483.153, rtol=1e-5)
# Test 'cost' method
cost = generator.cost(y, mask)
assert cost.ndim == 0
cost_val = theano.function([y, mask], cost)(y_test, m_test)
assert_allclose(cost_val, 16.105, rtol=1e-5)
# Test 'AUXILIARY' variable 'per_sequence_element' in 'cost' method
cg = ComputationGraph([cost])
var_filter = VariableFilter(roles=[AUXILIARY])
aux_var_name = '_'.join(
[generator.name, generator.cost.name, 'per_sequence_element'])
cost_per_el = [
el for el in var_filter(cg.variables) if el.name == aux_var_name
][0]
assert cost_per_el.ndim == 0
cost_per_el_val = theano.function([y, mask], [cost_per_el])(y_test, m_test)
assert_allclose(cost_per_el_val, 1.61051, rtol=1e-5)
# Test generate
states, outputs, lm_states, costs = generator.generate(
iterate=True, batch_size=batch_size, n_steps=n_steps)
cg = ComputationGraph([states, outputs, costs])
states_val, outputs_val, costs_val = theano.function(
[], [states, outputs, costs], updates=cg.updates)()
assert states_val.shape == (n_steps, batch_size, dim)
assert outputs_val.shape == (n_steps, batch_size)
assert outputs_val.dtype == 'int64'
assert costs_val.shape == (n_steps, batch_size)
assert_allclose(states_val.sum(), -4.88367, rtol=1e-5)
assert_allclose(costs_val.sum(), 486.681, rtol=1e-5)
assert outputs_val.sum() == 627
# Test masks agnostic results of cost
cost1 = costs_fun([[1], [2]], [[1], [1]])[0]
cost2 = costs_fun([[3, 1], [4, 2], [2, 0]], [[1, 1], [1, 1], [1, 0]])[0]
assert_allclose(cost1.sum(), cost2[:, 1].sum(), rtol=1e-5)
def main(config):
vocab_src, _ = text_to_dict([config['train_src'],
config['dev_src'], config['test_src']])
vocab_tgt, cabvo = text_to_dict([config['train_tgt'],
config['dev_tgt']])
# Create Theano variables
logger.info('Creating theano variables')
source_sentence = tensor.lmatrix('source')
source_sentence_mask = tensor.matrix('source_mask')
target_sentence = tensor.lmatrix('target')
target_sentence_mask = tensor.matrix('target_mask')
source_sentence.tag.test_value = [[13, 20, 0, 20, 0, 20, 0],
[1, 4, 8, 4, 8, 4, 8],]
source_sentence_mask.tag.test_value = [[0, 1, 0, 1, 0, 1, 0],
[1, 0, 1, 0, 1, 0, 1],]
target_sentence.tag.test_value = [[0,1,1,5],
[2,0,1,0],]
target_sentence_mask.tag.test_value = [[0,1,1,0],
[1,1,1,0],]
logger.info('Building RNN encoder-decoder')
### Building Encoder
embedder = LookupTable(
length=len(vocab_src),
dim=config['embed_src'],
weights_init=IsotropicGaussian(),
biases_init=Constant(0.0),
name='embedder')
transformer = Linear(
config['embed_src'],
config['hidden_src']*4,
weights_init=IsotropicGaussian(),
biases_init=Constant(0.0),
name='transformer')
lstminit = np.asarray([0.0,]*config['hidden_src']+[0.0,]*config['hidden_src']+[1.0,]*config['hidden_src']+[0.0,]*config['hidden_src'])
encoder = Bidirectional(
LSTM(
dim=config['hidden_src'],
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(lstminit)),
name='encoderBiLSTM'
)
encoder.prototype.weights_init = Orthogonal()
### Building Decoder
lstminit = np.asarray([0.0,]*config['hidden_tgt']+[0.0,]*config['hidden_tgt']+[1.0,]*config['hidden_tgt']+[0.0,]*config['hidden_tgt'])
transition = LSTM2GO(
attended_dim=config['hidden_tgt'],
dim=config['hidden_tgt'],
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(lstminit),
name='decoderLSTM')
attention = SequenceContentAttention(
state_names=transition.apply.states, # default activation is Tanh
state_dims=[config['hidden_tgt']],
attended_dim=config['hidden_src']*2,
match_dim=config['hidden_tgt'],
name="attention")
readout = Readout(
source_names=['states',
'feedback',
attention.take_glimpses.outputs[0]],
readout_dim=len(vocab_tgt),
emitter = SoftmaxEmitter(
name='emitter'),
feedback_brick = LookupFeedback(
num_outputs=len(vocab_tgt),
feedback_dim=config['embed_tgt'],
name='feedback'),
post_merge=InitializableFeedforwardSequence([
Bias(dim=config['hidden_tgt'],
name='softmax_bias').apply,
Linear(input_dim=config['hidden_tgt'],
output_dim=config['embed_tgt'],
use_bias=False,
name='softmax0').apply,
Linear(input_dim=config['embed_tgt'],
name='softmax1').apply]),
merged_dim=config['hidden_tgt'])
decoder = SequenceGenerator(
readout=readout,
transition=transition,
attention=attention,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator",
fork=Fork(
[name for name in transition.apply.sequences if name != 'mask'],
prototype=Linear()),
add_contexts=True)
decoder.transition.weights_init = Orthogonal()
#printchildren(encoder, 1)
# Initialize model
logger.info('Initializing model')
embedder.initialize()
transformer.initialize()
encoder.initialize()
decoder.initialize()
# Apply model
embedded = embedder.apply(source_sentence)
tansformed = transformer.apply(embedded)
encoded = encoder.apply(tansformed)[0]
generated = decoder.generate(
n_steps=2*source_sentence.shape[1],
batch_size=source_sentence.shape[0],
attended = encoded.dimshuffle(1,0,2),
attended_mask=tensor.ones(source_sentence.shape).T
)
print 'Generated: ', generated
# generator_generate_outputs
#samples = generated[1] # For GRU
samples = generated[2] # For LSTM
samples.name = 'samples'
#samples_cost = generated[4] # For GRU
samples_cost = generated[5] # For LSTM
samples_cost = 'sampling_cost'
cost = decoder.cost(
mask = target_sentence_mask.T,
outputs = target_sentence.T,
attended = encoded.dimshuffle(1,0,2),
attended_mask = source_sentence_mask.T)
cost.name = 'target_cost'
cost.tag.aggregation_scheme = TakeLast(cost)
model = Model(cost)
logger.info('Creating computational graph')
cg = ComputationGraph(cost)
# apply dropout for regularization
if config['dropout'] < 1.0: # dropout is applied to the output of maxout in ghog
logger.info('Applying dropout')
dropout_inputs = [x for x in cg.intermediary_variables if x.name == 'maxout_apply_output']
cg = apply_dropout(cg, dropout_inputs, config['dropout'])
########
# Print shapes
shapes = [param.get_value().shape for param in cg.parameters]
logger.info("Parameter shapes: ")
for shape, count in Counter(shapes).most_common():
logger.info(' {:15}: {}'.format(shape, count))
logger.info("Total number of parameters: {}".format(len(shapes)))
printchildren(embedder, 1)
printchildren(transformer, 1)
printchildren(encoder, 1)
printchildren(decoder, 1)
# Print parameter names
# enc_dec_param_dict = merge(Selector(embedder).get_parameters(), Selector(encoder).get_parameters(), Selector(decoder).get_parameters())
# enc_dec_param_dict = merge(Selector(decoder).get_parameters())
# logger.info("Parameter names: ")
# for name, value in enc_dec_param_dict.items():
# logger.info(' {:15}: {}'.format(value.get_value().shape, name))
# logger.info("Total number of parameters: {}".format(len(enc_dec_param_dict)))
##########
# Training data
train_stream = get_train_stream(config,
[config['train_src'],], [config['train_tgt'],],
vocab_src, vocab_tgt)
dev_stream = get_dev_stream(
[config['dev_src'],], [config['dev_tgt'],],
vocab_src, vocab_tgt)
test_stream = get_test_stream([config['test_src'],], vocab_src)
# Set extensions
logger.info("Initializing extensions")
extensions = [
FinishAfter(after_n_batches=config['finish_after']),
ProgressBar(),
TrainingDataMonitoring([cost],
prefix="tra",
after_batch=True),
DataStreamMonitoring(variables=[cost],
data_stream=dev_stream,
prefix="dev",
after_batch=True),
Sampler(
model=Model(samples),
data_stream=dev_stream,
vocab=cabvo,
saveto=config['saveto']+'dev',
every_n_batches=config['save_freq']),
Sampler(
model=Model(samples),
data_stream=test_stream,
vocab=cabvo,
saveto=config['saveto']+'test',
after_n_batches=1,
on_resumption=True,
before_training=True),
Plotter(saveto=config['saveto'], after_batch=True),
Printing(after_batch=True),
Checkpoint(
path=config['saveto'],
parameters = cg.parameters,
save_main_loop=False,
every_n_batches=config['save_freq'])]
if BOKEH_AVAILABLE:
Plot('Training cost', channels=[['target_cost']], after_batch=True)
if config['reload']:
extensions.append(Load(path=config['saveto'],
load_iteration_state=False,
load_log=False))
else:
with open(config['saveto']+'.txt', 'w') as f:
pass
# Set up training algorithm
logger.info("Initializing training algorithm")
algorithm = GradientDescent(cost=cost,
parameters=cg.parameters,
step_rule=CompositeRule([StepClipping(config['step_clipping']),
eval(config['step_rule'])()])
)
# Initialize main loop
logger.info("Initializing main loop")
main_loop = MainLoop(
model=model,
algorithm=algorithm,
data_stream=train_stream,
extensions=extensions)
main_loop.run()
def __init__(self):
SoftmaxEmitter.__init__(self)
self.theano_rng = MRG_RandomStreams(seed=random.randint(0, 100000))
def __init__(self):
SoftmaxEmitter.__init__(self)
self.theano_rng = MRG_RandomStreams(seed=random.randint(0,100000))
def main(mode, save_path, steps, num_batches):
num_states = MarkovChainDataset.num_states
if mode == "train":
# Experiment configuration
rng = numpy.random.RandomState(1)
batch_size = 50
seq_len = 100
dim = 10
feedback_dim = 8
# Build the bricks and initialize them
transition = GatedRecurrent(name="transition",
dim=dim,
activation=Tanh())
generator = SequenceGenerator(Readout(
readout_dim=num_states,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(num_states,
feedback_dim,
name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
# Give an idea of what's going on.
logger.info("Parameters:\n" + pprint.pformat(
[(key, value.get_value().shape)
for key, value in Selector(generator).get_params().items()],
width=120))
logger.info("Markov chain entropy: {}".format(
MarkovChainDataset.entropy))
logger.info("Expected min error: {}".format(
-MarkovChainDataset.entropy * seq_len))
# Build the cost computation graph.
x = tensor.lmatrix('data')
cost = aggregation.mean(
generator.cost_matrix(x[:, :]).sum(), x.shape[1])
cost.name = "sequence_log_likelihood"
algorithm = GradientDescent(
cost=cost,
params=list(Selector(generator).get_params().values()),
step_rule=Scale(0.001))
main_loop = MainLoop(algorithm=algorithm,
data_stream=DataStream(
MarkovChainDataset(rng, seq_len),
iteration_scheme=ConstantScheme(batch_size)),
model=Model(cost),
extensions=[
FinishAfter(after_n_batches=num_batches),
TrainingDataMonitoring([cost],
prefix="this_step",
after_batch=True),
TrainingDataMonitoring([cost],
prefix="average",
every_n_batches=100),
Checkpoint(save_path, every_n_batches=500),
Printing(every_n_batches=100)
])
main_loop.run()
elif mode == "sample":
main_loop = cPickle.load(open(save_path, "rb"))
generator = main_loop.model
sample = ComputationGraph(
generator.generate(n_steps=steps, batch_size=1,
iterate=True)).get_theano_function()
states, outputs, costs = [data[:, 0] for data in sample()]
numpy.set_printoptions(precision=3, suppress=True)
print("Generation cost:\n{}".format(costs.sum()))
freqs = numpy.bincount(outputs).astype(floatX)
freqs /= freqs.sum()
print("Frequencies:\n {} vs {}".format(freqs,
MarkovChainDataset.equilibrium))
trans_freqs = numpy.zeros((num_states, num_states), dtype=floatX)
for a, b in zip(outputs, outputs[1:]):
trans_freqs[a, b] += 1
trans_freqs /= trans_freqs.sum(axis=1)[:, None]
print("Transition frequencies:\n{}\nvs\n{}".format(
trans_freqs, MarkovChainDataset.trans_prob))
else:
assert False
def __init__(self, config, vocab_size):
question = tensor.imatrix('question')
question_mask = tensor.imatrix('question_mask')
context = tensor.imatrix('context')
context_mask = tensor.imatrix('context_mask')
answer = tensor.ivector('answer')
candidates = tensor.imatrix('candidates')
candidates_mask = tensor.imatrix('candidates_mask')
bricks = []
question = question.dimshuffle(1, 0)
question_mask = question_mask.dimshuffle(1, 0)
context = context.dimshuffle(1, 0)
context_mask = context_mask.dimshuffle(1, 0)
# Embed questions and cntext
embed = LookupTable(vocab_size, config.embed_size, name='question_embed')
bricks.append(embed)
qembed = embed.apply(question)
cembed = embed.apply(context)
qlstms, qhidden_list = make_bidir_lstm_stack(qembed, config.embed_size, question_mask.astype(theano.config.floatX),
config.question_lstm_size, config.question_skip_connections, 'q')
clstms, chidden_list = make_bidir_lstm_stack(cembed, config.embed_size, context_mask.astype(theano.config.floatX),
config.ctx_lstm_size, config.ctx_skip_connections, 'ctx')
bricks = bricks + qlstms + clstms
# Calculate question encoding (concatenate layer1)
if config.question_skip_connections:
qenc_dim = 2*sum(config.question_lstm_size)
qenc = tensor.concatenate([h[-1,:,:] for h in qhidden_list], axis=1)
else:
qenc_dim = 2*config.question_lstm_size[-1]
qenc = tensor.concatenate([h[-1,:,:] for h in qhidden_list[-2:]], axis=1)
qenc.name = 'qenc'
# Calculate context encoding (concatenate layer1)
if config.ctx_skip_connections: #default yes
cenc_dim = 2*sum(config.ctx_lstm_size) #2 : fw & bw
cenc = tensor.concatenate(chidden_list, axis=2)
else:
cenc_dim = 2*config.ctx_lstm_size[-1]
cenc = tensor.concatenate(chidden_list[-2:], axis=2)
cenc.name = 'cenc'
# Attention mechanism MLP activation: Tanh, identity
attention_mlp = MLP(dims=config.attention_mlp_hidden + [1],
activations=config.attention_mlp_activations[1:] + [Identity()],
name='attention_mlp')
attention_qlinear = Linear(input_dim=qenc_dim, output_dim=config.attention_mlp_hidden[0], name='attq') #Wum
attention_clinear = Linear(input_dim=cenc_dim, output_dim=config.attention_mlp_hidden[0], use_bias=False, name='attc') # Wym
bricks += [attention_mlp, attention_qlinear, attention_clinear]
layer1 = Tanh().apply(attention_clinear.apply(cenc.reshape((cenc.shape[0]*cenc.shape[1], cenc.shape[2])))
.reshape((cenc.shape[0],cenc.shape[1],config.attention_mlp_hidden[0]))
+ attention_qlinear.apply(qenc)[None, :, :])
layer1.name = 'layer1'
att_weights = attention_mlp.apply(layer1.reshape((layer1.shape[0]*layer1.shape[1], layer1.shape[2])))
att_weights.name = 'att_weights_0'
att_weights = att_weights.reshape((layer1.shape[0], layer1.shape[1]))
att_weights.name = 'att_weights'
attended = tensor.sum(cenc * tensor.nnet.softmax(att_weights.T).T[:, :, None], axis=0)
attended.name = 'attended'
print("attended shape: %d" %attended.shape)
dimension = qenc_dim + cenc_dim
transition = SimpleRecurrent(activation=Tanh(),dim=dimension, name="transition")
readout = Readout(
readout_dim=vocab_size,
source_names=[transition.apply.states[0]],
emitter=SoftmaxEmitter(name="emitter"),
feedback_brick=LookupFeedback(vocab_size, dimension),
name="readout")
generator = SequenceGenerator(
readout=readout, transition=transition,
name="generator")
self.generator = generator
bricks += [generator]
cost = self.generator.cost()
# Now we can calculate our output
out_mlp = MLP(dims=[cenc_dim + qenc_dim] + config.out_mlp_hidden + [config.n_entities],
activations=config.out_mlp_activations + [Identity()],
name='out_mlp')
bricks += [out_mlp]
probs = out_mlp.apply(tensor.concatenate([attended, qenc], axis=1))
probs.name = 'probs'
is_candidate = tensor.eq(tensor.arange(config.n_entities, dtype='int32')[None, None, :],
tensor.switch(candidates_mask, candidates, -tensor.ones_like(candidates))[:, :, None]).sum(axis=1)
probs = tensor.switch(is_candidate, probs, -1000 * tensor.ones_like(probs))
# Calculate prediction, cost and error rate
pred = probs.argmax(axis=1)
cost = Softmax().categorical_cross_entropy(answer, probs).mean()
error_rate = tensor.neq(answer, pred).mean()
# Apply dropout
cg = ComputationGraph([cost, error_rate])
if config.w_noise > 0:
noise_vars = VariableFilter(roles=[WEIGHT])(cg)
cg = apply_noise(cg, noise_vars, config.w_noise)
if config.dropout > 0:
cg = apply_dropout(cg, qhidden_list + chidden_list, config.dropout)
[cost_reg, error_rate_reg] = cg.outputs
# Other stuff
cost_reg.name = cost.name = 'cost'
error_rate_reg.name = error_rate.name = 'error_rate'
self.sgd_cost = cost_reg
self.monitor_vars = [[cost_reg], [error_rate_reg]]
self.monitor_vars_valid = [[cost], [error_rate]]
# Initialize bricks
for brick in bricks:
brick.weights_init = config.weights_init
brick.biases_init = config.biases_init
brick.initialize()
def test_integer_sequence_generator():
"""Test a sequence generator with integer outputs.
Such sequence generators can be used to e.g. model language.
"""
rng = numpy.random.RandomState(1234)
readout_dim = 5
feedback_dim = 3
dim = 20
batch_size = 30
n_steps = 10
transition = GatedRecurrent(dim=dim, activation=Tanh(),
weights_init=Orthogonal())
generator = SequenceGenerator(
Readout(readout_dim=readout_dim, source_names=["states"],
emitter=SoftmaxEmitter(theano_seed=1234),
feedback_brick=LookupFeedback(readout_dim,
feedback_dim)),
transition,
weights_init=IsotropicGaussian(0.1), biases_init=Constant(0),
seed=1234)
generator.initialize()
# Test 'cost_matrix' method
y = tensor.lmatrix('y')
mask = tensor.matrix('mask')
costs = generator.cost_matrix(y, mask)
assert costs.ndim == 2
costs_fun = theano.function([y, mask], [costs])
y_test = rng.randint(readout_dim, size=(n_steps, batch_size))
m_test = numpy.ones((n_steps, batch_size), dtype=floatX)
costs_val = costs_fun(y_test, m_test)[0]
assert costs_val.shape == (n_steps, batch_size)
assert_allclose(costs_val.sum(), 482.827, rtol=1e-5)
# Test 'cost' method
cost = generator.cost(y, mask)
assert cost.ndim == 0
cost_val = theano.function([y, mask], [cost])(y_test, m_test)
assert_allclose(cost_val, 16.0942, rtol=1e-5)
# Test 'AUXILIARY' variable 'per_sequence_element' in 'cost' method
cg = ComputationGraph([cost])
var_filter = VariableFilter(roles=[AUXILIARY])
aux_var_name = '_'.join([generator.name, generator.cost.name,
'per_sequence_element'])
cost_per_el = [el for el in var_filter(cg.variables)
if el.name == aux_var_name][0]
assert cost_per_el.ndim == 0
cost_per_el_val = theano.function([y, mask], [cost_per_el])(y_test, m_test)
assert_allclose(cost_per_el_val, 1.60942, rtol=1e-5)
# Test generate
states, outputs, costs = generator.generate(
iterate=True, batch_size=batch_size, n_steps=n_steps)
cg = ComputationGraph(states + outputs + costs)
states_val, outputs_val, costs_val = theano.function(
[], [states, outputs, costs],
updates=cg.updates)()
assert states_val.shape == (n_steps, batch_size, dim)
assert outputs_val.shape == (n_steps, batch_size)
assert outputs_val.dtype == 'int64'
assert costs_val.shape == (n_steps, batch_size)
assert_allclose(states_val.sum(), -17.91811, rtol=1e-5)
assert_allclose(costs_val.sum(), 482.863, rtol=1e-5)
assert outputs_val.sum() == 630
# Test masks agnostic results of cost
cost1 = costs_fun([[1], [2]], [[1], [1]])[0]
cost2 = costs_fun([[3, 1], [4, 2], [2, 0]],
[[1, 1], [1, 1], [1, 0]])[0]
assert_allclose(cost1.sum(), cost2[:, 1].sum(), rtol=1e-5)
def test_softmax_emitter_initial_outputs():
emitter = SoftmaxEmitter(3)
emitter.readout_dim = 0
assert_equal(emitter.initial_outputs(2).eval(),
3 * numpy.ones((2,), dtype='int64'))
def main(mode, save_path, steps, time_budget, reset):
num_states = ChainDataset.num_states
if mode == "train":
# Experiment configuration
rng = numpy.random.RandomState(1)
batch_size = 50
seq_len = 100
dim = 10
feedback_dim = 8
# Build the bricks and initialize them
transition = GatedRecurrent(name="transition", activation=Tanh(),
dim=dim)
generator = SequenceGenerator(
LinearReadout(readout_dim=num_states, source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(
num_states, feedback_dim, name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01), biases_init=Constant(0),
name="generator")
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
logger.info("Parameters:\n" +
pprint.pformat(
[(key, value.get_value().shape) for key, value
in Selector(generator).get_params().items()],
width=120))
logger.info("Markov chain entropy: {}".format(
ChainDataset.entropy))
logger.info("Expected min error: {}".format(
-ChainDataset.entropy * seq_len * batch_size))
if os.path.isfile(save_path) and not reset:
model = Pylearn2Model.load(save_path)
else:
model = Pylearn2Model(generator)
# Build the cost computation graph.
# Note: would be probably nicer to make cost part of the model.
x = tensor.ltensor3('x')
cost = Pylearn2Cost(model.brick.cost(x[:, :, 0]).sum())
dataset = ChainDataset(rng, seq_len)
sgd = SGD(learning_rate=0.0001, cost=cost,
batch_size=batch_size, batches_per_iter=10,
monitoring_dataset=dataset,
monitoring_batch_size=batch_size,
monitoring_batches=1,
learning_rule=Pylearn2LearningRule(
SGDLearningRule(),
dict(training_objective=cost.cost)))
train = Pylearn2Train(dataset, model, algorithm=sgd,
save_path=save_path, save_freq=10)
train.main_loop(time_budget=time_budget)
elif mode == "sample":
model = Pylearn2Model.load(save_path)
generator = model.brick
sample = ComputationGraph(generator.generate(
n_steps=steps, batch_size=1, iterate=True)).function()
states, outputs, costs = [data[:, 0] for data in sample()]
numpy.set_printoptions(precision=3, suppress=True)
print("Generation cost:\n{}".format(costs.sum()))
freqs = numpy.bincount(outputs).astype(floatX)
freqs /= freqs.sum()
print("Frequencies:\n {} vs {}".format(freqs,
ChainDataset.equilibrium))
trans_freqs = numpy.zeros((num_states, num_states), dtype=floatX)
for a, b in zip(outputs, outputs[1:]):
trans_freqs[a, b] += 1
trans_freqs /= trans_freqs.sum(axis=1)[:, None]
print("Transition frequencies:\n{}\nvs\n{}".format(
trans_freqs, ChainDataset.trans_prob))
else:
assert False
def __init__(self,
vocab_size,
embedding_dim,
state_dim,
representation_dim,
context_dim,
target_transition,
theano_seed=None,
loss_function='cross_entropy',
**kwargs):
super(InitialContextDecoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = target_transition(attended_dim=state_dim,
context_dim=context_dim,
dim=state_dim,
activation=Tanh(),
name='decoder')
# self.transition = GRUInitialStateWithInitialStateConcatContext(
# attended_dim=state_dim, context_dim=context_dim, dim=state_dim,
# activation=Tanh(), name='decoder')
# Initialize the attention mechanism
self.attention = SequenceContentAttention(
state_names=self.transition.apply.states,
attended_dim=representation_dim,
match_dim=state_dim,
name="attention")
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
readout = Readout(
source_names=[
'states',
'feedback',
# Chris: it's key that we're taking the first output of self.attention.take_glimpses.outputs
# Chris: the first output is the weighted avgs, the second is the weights in (batch, time)
self.attention.take_glimpses.outputs[0]
],
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1, theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(vocab_size, embedding_dim),
post_merge=InitializableFeedforwardSequence([
Bias(dim=state_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=state_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply
]),
merged_dim=state_dim)
# Build sequence generator accordingly
if loss_function == 'cross_entropy':
self.sequence_generator = InitialContextSequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name for name in self.transition.apply.sequences
if name != 'mask'
],
prototype=Linear()))
elif loss_function == 'min_risk':
self.sequence_generator = MinRiskInitialContextSequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name for name in self.transition.apply.sequences
if name != 'mask'
],
prototype=Linear()))
# the name is important, because it lets us match the brick hierarchy names for the vanilla SequenceGenerator
# to load pretrained models
# TODO: quick hack to fix bug
self.sequence_generator.name = 'initialcontextsequencegenerator'
else:
raise ValueError(
'The decoder does not support the loss function: {}'.format(
loss_function))
# TODO: uncomment this!!
# self.sequence_generator.name = 'sequencegenerator'
self.children = [self.sequence_generator]
def __init__(
self,
recordings_source,
labels_source,
eos_label,
num_features,
num_phonemes,
dim_dec,
dims_bidir,
dims_bottom,
enc_transition,
dec_transition,
use_states_for_readout,
attention_type,
lm=None,
character_map=None,
subsample=None,
dims_top=None,
prior=None,
conv_n=None,
bottom_activation=None,
post_merge_activation=None,
post_merge_dims=None,
dim_matcher=None,
embed_outputs=True,
dec_stack=1,
conv_num_filters=1,
data_prepend_eos=True,
energy_normalizer=None, # softmax is th edefault set in SequenceContentAndConvAttention
**kwargs):
if bottom_activation is None:
bottom_activation = Tanh()
if post_merge_activation is None:
post_merge_activation = Tanh()
super(SpeechRecognizer, self).__init__(**kwargs)
self.recordings_source = recordings_source
self.labels_source = labels_source
self.eos_label = eos_label
self.data_prepend_eos = data_prepend_eos
self.rec_weights_init = None
self.initial_states_init = None
self.enc_transition = enc_transition
self.dec_transition = dec_transition
self.dec_stack = dec_stack
bottom_activation = bottom_activation
post_merge_activation = post_merge_activation
if dim_matcher is None:
dim_matcher = dim_dec
# The bottom part, before BiRNN
if dims_bottom:
bottom = MLP([bottom_activation] * len(dims_bottom),
[num_features] + dims_bottom,
name="bottom")
else:
bottom = Identity(name='bottom')
# BiRNN
if not subsample:
subsample = [1] * len(dims_bidir)
encoder = Encoder(
self.enc_transition, dims_bidir,
dims_bottom[-1] if len(dims_bottom) else num_features, subsample)
# The top part, on top of BiRNN but before the attention
if dims_top:
top = MLP([Tanh()],
[2 * dims_bidir[-1]] + dims_top + [2 * dims_bidir[-1]],
name="top")
else:
top = Identity(name='top')
if dec_stack == 1:
transition = self.dec_transition(dim=dim_dec,
activation=Tanh(),
name="transition")
else:
transitions = [
self.dec_transition(dim=dim_dec,
activation=Tanh(),
name="transition_{}".format(trans_level))
for trans_level in xrange(dec_stack)
]
transition = RecurrentStack(transitions=transitions,
skip_connections=True)
# Choose attention mechanism according to the configuration
if attention_type == "content":
attention = SequenceContentAttention(
state_names=transition.apply.states,
attended_dim=2 * dims_bidir[-1],
match_dim=dim_matcher,
name="cont_att")
elif attention_type == "content_and_conv":
attention = SequenceContentAndConvAttention(
state_names=transition.apply.states,
conv_n=conv_n,
conv_num_filters=conv_num_filters,
attended_dim=2 * dims_bidir[-1],
match_dim=dim_matcher,
prior=prior,
energy_normalizer=energy_normalizer,
name="conv_att")
else:
raise ValueError(
"Unknown attention type {}".format(attention_type))
if embed_outputs:
feedback = LookupFeedback(num_phonemes + 1, dim_dec)
else:
feedback = OneOfNFeedback(num_phonemes + 1)
if lm:
# In case we use LM it is Readout that is responsible
# for normalization.
emitter = LMEmitter()
else:
emitter = SoftmaxEmitter(initial_output=num_phonemes,
name="emitter")
readout_config = dict(readout_dim=num_phonemes,
source_names=(transition.apply.states if
use_states_for_readout else []) +
[attention.take_glimpses.outputs[0]],
emitter=emitter,
feedback_brick=feedback,
name="readout")
if post_merge_dims:
readout_config['merged_dim'] = post_merge_dims[0]
readout_config['post_merge'] = InitializableSequence(
[
Bias(post_merge_dims[0]).apply,
post_merge_activation.apply,
MLP(
[post_merge_activation] *
(len(post_merge_dims) - 1) + [Identity()],
# MLP was designed to support Maxout is activation
# (because Maxout in a way is not one). However
# a single layer Maxout network works with the trick below.
# For deeper Maxout network one has to use the
# Sequence brick.
[
d //
getattr(post_merge_activation, 'num_pieces', 1)
for d in post_merge_dims
] + [num_phonemes]).apply,
],
name='post_merge')
readout = Readout(**readout_config)
language_model = None
if lm:
lm_weight = lm.pop('weight', 0.0)
normalize_am_weights = lm.pop('normalize_am_weights', True)
normalize_lm_weights = lm.pop('normalize_lm_weights', False)
normalize_tot_weights = lm.pop('normalize_tot_weights', False)
am_beta = lm.pop('am_beta', 1.0)
if normalize_am_weights + normalize_lm_weights + normalize_tot_weights < 1:
logger.warn(
"Beam search is prone to fail with no log-prob normalization"
)
language_model = LanguageModel(nn_char_map=character_map, **lm)
readout = ShallowFusionReadout(
lm_costs_name='lm_add',
lm_weight=lm_weight,
normalize_am_weights=normalize_am_weights,
normalize_lm_weights=normalize_lm_weights,
normalize_tot_weights=normalize_tot_weights,
am_beta=am_beta,
**readout_config)
generator = SequenceGenerator(readout=readout,
transition=transition,
attention=attention,
language_model=language_model,
name="generator")
# Remember child bricks
self.encoder = encoder
self.bottom = bottom
self.top = top
self.generator = generator
self.children = [encoder, top, bottom, generator]
# Create input variables
self.recordings = tensor.tensor3(self.recordings_source)
self.recordings_mask = tensor.matrix(self.recordings_source + "_mask")
self.labels = tensor.lmatrix(self.labels_source)
self.labels_mask = tensor.matrix(self.labels_source + "_mask")
self.batch_inputs = [
self.recordings, self.recordings_source, self.labels,
self.labels_mask
]
self.single_recording = tensor.matrix(self.recordings_source)
self.single_transcription = tensor.lvector(self.labels_source)
def __init__(self,
vocab_size,
embedding_dim,
state_dim,
att_dim,
maxout_dim,
representation_dim,
attention_strategy='content',
attention_sources='s',
readout_sources='sfa',
memory='none',
memory_size=500,
seq_len=50,
init_strategy='last',
make_prunable=False,
theano_seed=None,
**kwargs):
"""Creates a new decoder brick.
Args:
vocab_size (int): Target language vocabulary size
embedding_dim (int): Size of feedback embedding layer
state_dim (int): Number of hidden units
att_dim (int): Size of attention match vector
maxout_dim (int): Size of maxout layer
representation_dim (int): Dimension of source annotations
attention_strategy (string): Which attention should be used
cf. ``_initialize_attention``
attention_sources (string): Defines the sources used by the
attention model 's' for decoder
states, 'f' for feedback
readout_sources (string): Defines the sources used in the
readout network. 's' for decoder
states, 'f' for feedback, 'a' for
attention (context vector)
memory (string): Which external memory should be used
(cf. ``_initialize_attention``)
memory_size (int): Size of the external memory structure
seq_len (int): Maximum sentence length
init_strategy (string): How to initialize the RNN state
(cf. ``GRUInitialState``)
theano_seed: Random seed
"""
super(Decoder, self).__init__(**kwargs)
self.vocab_size = vocab_size
self.embedding_dim = embedding_dim
self.state_dim = state_dim
self.representation_dim = representation_dim
self.theano_seed = theano_seed
# Initialize gru with special initial state
self.transition = GRUInitialState(attended_dim=representation_dim / 2,
init_strategy=init_strategy,
dim=state_dim,
activation=Tanh(),
name='decoder')
# Initialize the attention mechanism
att_dim = att_dim if att_dim > 0 else state_dim
self.attention, src_names = _initialize_attention(
attention_strategy, seq_len, self.transition, representation_dim,
att_dim, attention_sources, readout_sources, memory, memory_size)
# Initialize the readout, note that SoftmaxEmitter emits -1 for
# initial outputs which is used by LookupFeedBackWMT15
maxout_dim = maxout_dim if maxout_dim > 0 else state_dim
post_layers = [
Bias(dim=maxout_dim, name='maxout_bias').apply,
Maxout(num_pieces=2, name='maxout').apply,
Linear(input_dim=maxout_dim / 2,
output_dim=embedding_dim,
use_bias=False,
name='softmax0').apply,
Linear(input_dim=embedding_dim, name='softmax1').apply
]
if make_prunable:
post_merge = PrunableInitializableFeedforwardSequence(post_layers)
else:
post_merge = InitializableFeedforwardSequence(post_layers)
readout = Readout(source_names=src_names,
readout_dim=self.vocab_size,
emitter=SoftmaxEmitter(initial_output=-1,
theano_seed=theano_seed),
feedback_brick=LookupFeedbackWMT15(
vocab_size, embedding_dim),
post_merge=post_merge,
merged_dim=maxout_dim)
# Build sequence generator accordingly
if make_prunable:
self.sequence_generator = PrunableSequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name for name in self.transition.apply.sequences
if name != 'mask'
],
prototype=Linear()))
else:
self.sequence_generator = SequenceGenerator(
readout=readout,
transition=self.transition,
attention=self.attention,
fork=Fork([
name for name in self.transition.apply.sequences
if name != 'mask'
],
prototype=Linear()))
self.children = [self.sequence_generator]
def main():
logging.basicConfig(
level=logging.DEBUG,
format="%(asctime)s: %(name)s: %(levelname)s: %(message)s")
parser = argparse.ArgumentParser(
"Case study of generating a Markov chain with RNN.",
formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument(
"mode",
choices=["train", "sample"],
help="The mode to run. Use `train` to train a new model"
" and `sample` to sample a sequence generated by an"
" existing one.")
parser.add_argument("prefix",
default="sine",
help="The prefix for model, timing and state files")
parser.add_argument("--steps",
type=int,
default=100,
help="Number of steps to plot")
args = parser.parse_args()
dim = 10
num_states = ChainIterator.num_states
feedback_dim = 8
transition = GatedRecurrent(name="transition", activation=Tanh(), dim=dim)
generator = SequenceGenerator(LinearReadout(
readout_dim=num_states,
source_names=["states"],
emitter=SoftmaxEmitter(name="emitter"),
feedbacker=LookupFeedback(num_states, feedback_dim, name='feedback'),
name="readout"),
transition,
weights_init=IsotropicGaussian(0.01),
biases_init=Constant(0),
name="generator")
generator.allocate()
logger.debug("Parameters:\n" + pprint.pformat(
[(key, value.get_value().shape)
for key, value in Selector(generator).get_params().items()],
width=120))
if args.mode == "train":
rng = numpy.random.RandomState(1)
batch_size = 50
generator.push_initialization_config()
transition.weights_init = Orthogonal()
generator.initialize()
logger.debug("transition.weights_init={}".format(
transition.weights_init))
cost = generator.cost(tensor.lmatrix('x')).sum()
gh_model = GroundhogModel(generator, cost)
state = GroundhogState(args.prefix, batch_size,
learning_rate=0.0001).as_dict()
data = ChainIterator(rng, 100, batch_size)
trainer = SGD(gh_model, state, data)
main_loop = MainLoop(data, None, None, gh_model, trainer, state, None)
main_loop.main()
elif args.mode == "sample":
load_params(generator, args.prefix + "model.npz")
sample = ComputationGraph(
generator.generate(n_steps=args.steps, batch_size=1,
iterate=True)).function()
states, outputs, costs = [data[:, 0] for data in sample()]
numpy.set_printoptions(precision=3, suppress=True)
print("Generation cost:\n{}".format(costs.sum()))
freqs = numpy.bincount(outputs).astype(floatX)
freqs /= freqs.sum()
print("Frequencies:\n {} vs {}".format(freqs,
ChainIterator.equilibrium))
trans_freqs = numpy.zeros((num_states, num_states), dtype=floatX)
for a, b in zip(outputs, outputs[1:]):
trans_freqs[a, b] += 1
trans_freqs /= trans_freqs.sum(axis=1)[:, None]
print("Transition frequencies:\n{}\nvs\n{}".format(
trans_freqs, ChainIterator.trans_prob))
else:
assert False
